Whether it is the ancient wisdom, past tradition or culture or the modern scientific research, all confirms and validates the beneficial effects of olive oil on cardiovascular diseases. In some of my other articles, I have shown how olive oil, especially extra virgin, can treat conditions like cancer, pains, arthritis and digestive orders. This post is solely dedicated to olive oil in relation to heart, coronary or cardiovascular diseases.
According to the National Institute of Health USA, heart disease is the number 1 killer of people in America. Not only is it the top killer, it is also a major cause of disability. According the NHS UK, one in five men and one in eight women die from coronary heart disease (CHD). Every two minute in the UK, someone has a heart attack. The main cause of coronary heart diseases is blockage of the coronary arteries. These are the vessels which supply blood to the heart. Overtime, these vessels become narrow or blocked. Disease caused by the blockage or narrowing of arteries is called coronary artery disease which is a major cause behind most people’s heart attacks.
There are seven main factors contributing to coronary heart diseases. These are
- High Blood Pressure
- High Cholesterol
- Physical Inactivity
- Being Overweight
- Family history
The Role of Cholesterol
Cholesterol is also known as lipid. These are fatty substances made by the liver. These are also found in certain foods. Proteins in the blood carry cholesterol. So when proteins combine with cholesterol (lipids), they are called lipoproteins. There are two kinds of lipoproteins: LDL and HDL. The LDL is low-density lipoprotein and they carry cholesterol from the liver to the cell. When the amount of LDL becomes too much, they start building up in the arteries causing arterial diseases. As high level of LDL cause disease of the arteries, they are also known as harmful or bad cholesterols. The HDL is the high density cholesterols and they carry cholesterol from the cells to the liver. They are either broken down in the liver or passed out of the body as waste products. HDL plays a role in getting the body rid off cholesterol, it is, therefore also known as protective or good cholesterols.
How Does Olive Oil Help?
Olive oil lowers the total levels of cholesterol, yet it does not lowers the level of HDL (the protective and good cholesterol) Acceding to experts, olive oil lowers LDL and raises HDL which protects the arteries from plaque building. This prevents heart diseases like angina, stroke and heart attack. Monounsaturated fat plays an important role in bringing the levels of cholesterol into balance. Around 80% percent of the fatty content in extra virgin olive oil (EVOO) is monounsaturated fat which lowers the cholesterol levels in the blood with a positive effect on the blood lipids. The human body needs all three types of fatty acids: saturated, polyunsaturated and monounsaturated. However, this must be in the right proportion. Virgin olive oil contains all these three fatty acids in the right proportion. Unlike animal fat or most vegetable fat, the fat in olive oil contains absolutely no cholesterol. So, replacing the other dietary fat with EVOO has a double advantage: it does not add to the existing cholesterol level and it also reduces the LDL.
Proponents of olive oil experts suggest that those who want to reduce their health risks as much as possible and protect themselves against conditions like cardiovascular diseases, high blood pressure, high cholesterol, diabetes, cancers etc, they should eliminate animal fat altogether and replace it with olive oil.
What Does Research Say?
Numerous studies have been conducted to investigate the beneficial effects of the oil for heart and to prevent or stop diseases associated with this super organ. As time advances, more and more studies are being conducted with new findings and opening new ways for further investigation. Here, I have referred to some of studies which are most relevant to the subject of this post.
1. Classic International Study
Ancel Keys conducted a study back in 1950s in which he compared diet and rates of heart diseases among the people from seven different countries. The study was published by Cambridge Harward University Press in 1980 under the name “Seven Countries: A Multivariate Analysis of Death and Coronary Heart Diseases.” The study is one of its kinds as it involved 12000 middle aged people and it lasted for 30 years. The study found that the least heart diseases were found among the people of Crete and Corfu, on the Greek Islands. The Cretan people diet consisted of vegetables, fruit, whole grain and olive oil as the main sources of calories. It was also found that mortality rate was the lowest among the Greeks where olive oil was the top ingredient of their diet. On the other hand, people from Japan, America and Northern Europe had higher rate of mortality as their food main source was meat with no or little olive oil ingredients.
2. The Jerusalem Nutrition Study
Berry EM, Eisdenber S, Friedlander Y et al, did a study in which two groups of healthy college students were given diets for 12 weeks. In one group fat was added to the diet in the form of olive oil, avocado or almonds while in the other group it was supplemented with carbohydrates rich food items. It was found that the group on the MUFA showed a significant decrease in plasma and LDL cholesterol while the group on carbohydrate diet did not show any significant change. The study was published in the American Journal of Clinical Nutrition in 1992.
3. JAMA Studies 1987 & 1990
The Journal of the American Medical Association (JAMA) published an article in 1987 under the title “Association of dietary fat, regional adiposity, and blood pressure in men”. The article discussed a study which investigated the effect of oleic acid. It was found that oleic acid in olive oil was a major fatty acid with blood pressuring lowering effect.
Another study which was published in the Journal of American Medical Association in 1990, the investigators selected individuals aged between 30 and 55 to study the effect of taking high amount of monounsaturated fat in the form olive oil on high blood pressure. The results were very impressive as it was found that MUFAs were associated with lower blood pressure. It lowered both the systolic and diastolic levels. The study found that the major fatty acid in olive oil is oleic acid which is a monounsaturated fat responsible for lowering blood pressure.
4. Report of the National Cholesterol Education Program
This is the report of the NCEP expert panel published by Archives of Internal Medicine (Arch Intern Med) in 1988 under the title “Detection, Evaluation and Treatment of High Blood Cholesterol in adults”. The panel developed a dietary guideline which clearly stated that oleic acid (found in olive oil) should form the major fatty acid of a healthy diet to prevent coronary diseases.
5. Study on Smokers
Another study investigated the role of olive oil in preventing heart attack recurrence to those who already had suffered an attack before. One group was given diet rich in alpha-linolenic and oleic acids. The group continued to take regular diets. The study continued for 27 months. The researchers found that the first group who took alpaha-linolenic and oleic acids, there were only three people who died of a second heart attack. This number of people in the regular diet group was 16, which was a lot higher. For the purpose of the study, more smokers were included in the first group. This showed that the two fatty acids even helped to prevent the coronary diseases in smokers.
6. Nurses Health Study
This is one of the gigantic studies in which more than 80,000 women participated. The women took 80 calories of monounsaturated or polyunsaturated fat as substitute for 80 calories of carbohydrate. The results were amazing. It was found that the heart disease risk was lowered by 30 to 40 percent! The study was published in the New England Journal of Medicine 1997.
The European Journal of Clinical Nutrition reported in 2002 that people who consumed 2 tablespoon of virgin olive oil a day had less oxidation levels of LDL cholesterol. In another study, 200 men participated to find out the effects of olive on heart health. The study found that men who consumed 5 tablespoon of extra virgin olive oil as a substitute for the ordinary diet fat, had significantly lower blood pressure and the levels of bad cholesterol. This significantly reduced the risk of heart disease. The study was published in Annals of Internal Medicine, 2006.
7. Lyon Heart Study
It was a long term study in which patients who had previous infarcts were treated with diet based on EVOO. The results were astonishing. Patients who ate the EVOO based diet had 70% fewer heart attacks than the group of patients who were not given the same diet.
8. Recent Study in 2013
A recent study has just been published in The New England Journal of Medicine, 2013 and its story reported in New York Times on 25 Feb, 2013. More than 7000 people participated in the study which continued for 5 years. People were put on Mediteranean diet and were asked to consume 4 tablespoon of extra virgin olive oil every day. The study found that the group who consumed extra virgin olive oil was 30 percent at lower risk. The study was conducted on people who were already at high risk and were overweight, smokers or diabetic. Some medical quarters have termed the findings of the study as a triumph. Scientists from Spain collaborated with professors of Harvard School of Public Health to arrive at correct conclusions.
9. Other Studies
Clinical Cardiology reported in 2007, that the Greek study, which involved 1,926 people showed some amazing results. The study confirmed that people who made olive oil as their only dietary fat had reduced the risk of coronary diseases by half. In another overview the British Medical Journal reported in 2008 that stick adherence to Mediterranean diet reduced the chance of dying from heart attack by 9 percent. This overview consisted of 12 studies which involved over 1.5 million people! Another study was conducted in Italy in which 30,000 women participated. The women were divided into two groups. The first group consumed 3 tablespoon of olive oil daily, while the other group either did not take it or consumed much less. The results showed that the first group of women, who consumed 3 tablespoon of extra virgin olive oil everyday, had nearly half the risk of developing heart disease with the group which consumed less. The American Journal of Clinical Nutrition published the study in 2010.
The list of studies is much more comprehensive than mentioned here. However, we consider it enough for the reader to draw their own conclusions. The evidence of the positive effects of Olive Oil on cardiovascular diseases is not limited only to scientific studies. There is a vast list of anecdotal evidence reported from people who have been using EVOO or olive oil throughout their lives.
If you are already taking a lot of fat from other sources, it wont be wise just add more fat in the form of olive oil. The best way is to replace other fat by extra virgin olive oil. This way you are not only cutting on calories but adding healthy fatty acids to your diet. Exercise, vegetables, fruits and other healthy diet along with olive oil yield better health results.